Luar: Lua reflection bindings for Go

Luar is designed to make using Lua from Go more convenient. Go structs, slices and maps can be automatically converted to Lua tables and vice-versa. The resulting conversion can either be a copy or a proxy. In the latter case, any change made to the result will reflect on the source.

Any Go function can be made available to Lua scripts, without having to write C-style wrappers.

Luar support cyclic structures (map[string]interface{}, lists, etc.).

User-defined types can be made available to Lua as well: their exported methods can be called and usual operations such as indexing or arithmetic can be performed.

See the documentation for usage instructions and examples.

Installation

Install with

go get <repo>/luar

Luar uses Alessandro Arzilli's golua. See golua's homepage for further installation details.

REPL

Version 1.x features an example REPL that is available in the cmd folder.

Changelog

Luar 2

This is a rewrite of 1.x with extended features and a cleaner API. The main differences with the previous version:

• The function prototypes of GoToLua and LuaToGo are simpler and do not require the use of reflection from the callers. The dontproxify argument is gone, use GoToLuaProxy to control proxification.

• The Copy* functions and GoLuaFunc are gone, use GoToLua and LuaToGo instead.

• Use Register instead of RawRegister.

• InitProxies is gone since it was not needed.

• The LuaObject and LuaTableIter structure fields are unexported.

• LuaObject methods not only work on Lua functions but also on anything with a __call metamethods. Idem for tables and the __index/__newindex metamethods.

• Use NewLuaObjectFromName(L, "_G") instead of Global.

• Lookup and Geti gone. Instead the Get and GetObject functions are variadic: each subfield argument can be any valid Lua key (string, integer...).

• Use (*LuaObject) Call instead of (*LuaObject) Callf. The protoype of (*LuaObject) Call has changed in a fashion similar to GoToLua and LuaToGo. Types is gone as it is no longer needed.

• Register ProxyIpairs and ProxyPairs instead of calling LuarSetup.

• Register and use Unproxify instead of ArrayToTable, MapToTable, ProxyRaw, SliceToTable and StructToTable.

• ComplexReal and ComplexImag have been replaced by the proxy attributes real and imag, respectively.

• SliceSub and SliceAppend have been replaced by the proxy methods slice and append, respectively. Slice proxies have the cap metamethod alongside append and slice.

• String proxies have a slice method just like slice proxies. They can be looped rune-by-rune over with ipairs.

The range of supported conversion has been extended:

• LuaToGo can convert to interfaces and pointers with several levels of indirection.

• LuaToGo can convert to non-empty maps and structs.